This application claims benefit of Korean Patent Application No. 2001-33475, filed on Jun. 14, 2001 in the name of Jong-Hee Kim, the entirety of which is hereby incorporated by reference for all purposes as if fully set forth herein.
1. Field of the Invention
The present invention relates to semiconductor device fabricating equipment using radio frequency energy, and more particularly, to semiconductor device fabricating equipment using radio frequency energy which is capable of preventing a chamber""s respective portions containing a wafer from being polluted and damaged by various kinds of polymers deposited indiscriminately on the respective portions within the chamber.
2. Discussion of Related Art
In general, a semiconductor device is obtained by selectively and repetitively performing such processes as photolithography, etching, diffusion, chemical vapor deposition, ion injection and metallic depositions etc. on a wafer.
In semiconductor device fabricating equipment performing processes such as the etching, diffusion, chemical vapor deposition and metallic deposition, etc., the process is performed by converting a supplied process gas, through the use of radio frequency energy, into a plasma state, and by causing it to react on an upper surface of a wafer, or on a portion exposed from a pattern mask.
In such processes procedures of the semiconductor device fabricating equipment, a residual product, namely, polymer, is generated by a reaction of the process gas, and these polymers are consecutively deposited on an overall area provided under the processes, thus causing an obstruction in the process and, in the case that the polymer comes out of its deposited surface and moves onto the wafer, further reacting as a particle which causes a defect.
Before describing such polymer""s deposition relation and its influence, a conventional technical configuration of the semiconductor device fabricating equipment using the radio frequency energy will be described with reference to the accompanied drawings.
As shown in FIG. 1, in the conventional construction of the semiconductor device fabricating equipment using the radio frequency energy, there is a housing 10 which divides a given space, and an inner wall portion of this housing 10 is also divided into an upper housing 10a and a lower housing 10b, and these upper and lower housings 10a, 10b are formed as a fixing structure connected to another construction.
In the inner wall of the upper housing 10a, a shield 12 for covering a given area of the inner wall in the vertical direction is installed so that polymer P generated in the process procedure is not deposited on the inner wall of the upper housing 10a. 
Further, on an opened top of the housing 10, namely, an upper side ending portion of the upper housing 10a, an upper electrode part 14 is set, the upper electrode part 14 being assembled in a plate shape based on a constant thickness and applying the radio frequency energy. The inside of the upper and lower housings 10a, 10b have a closed atmosphere by the combination installation of the upper electrode part 14.
In the housing 10 beneath the upper electrode part 14, a chuck assembly is installed so as to be ascendible and descendible, the chuck assembly being for selectively fixing a provided and positioned wafer W and, containing a lower electrode part 16 which is confronted with the upper electrode part 14 and also applies the radio frequency energy.
Describing the construction of the chuck assembly more in detail, as shown in FIG. 1, in such a configuration, an upper surface edge portion of the lower electrode part 16 for closely supporting a lower surface of the wafer W is placed at a given distance from and centered with respect to a lower surface edge portion of the wafer W, and an outer upper surface edge of the lower electrode part 16 forms a stepped shape, based on a given thickness from an upper surface to a lower surface.
At this time, the lower electrode part 16 selectively absorption-fixes a lower surface of the wafer W close-supported on the upper face thereof by using static electricity force or vacuum pressure. As shown in FIG. 1 or FIG. 2, in the stepped portion of the lower electrode part 16, a focus ring 18 of a given shape is positioned so as to closely support a lower surface edge portion of the wafer W exposed by the upper surface of the lower electrode part 16, wherein the focus ring 18 is made of material the same as, or similar to, the wafer W and enlarges a distribution area so that the wafer W is positioned in a central portion of a radio frequency energy area from the lower electrode part 16.
Additionally, an insulation ring 20 for supporting a lower surface portion of the focus ring 18 is installed on an outer wall of the lower electrode part 16, extended and projected from the outside of the stepped portion of the lower electrode part 16. In a lower side portion of this insulation ring 20, a baffle plate 22, having numerous slits S formed therein, is set to control flow of the polymer into a lower part of the housing 10, the polymer being generated in the midst of executing the processes.
An outer ending portion of such installed baffle plate 22 is provided as a state closely positioned to an inner wall of the upper and lower housings 10, 10b with a given interval therebetween. In a lower portion of the baffle plate 22, a support member 24, made of dielectric material, is installed so as to shield a lower side portion of the chuck assembly containing the lower electrode part 16 from deposition of the polymer, and the baffle plate 22 is supported by an upper face of the support member 24.
Accordingly, during a process, the baffle plate 22 is positioned so as to ascend and descend by a driving of the chuck assembly so that an outer side portion of the baffle plate 22 becomes close to the side wall of the upper and lower housings 10, 10b. 
Describing the progression of a process in the above construction, when the wafer W is provided inside the housing 10 and is adhesion-fixed to an upper part of the chuck assembly, namely, an upper surface of the lower electrode part 16 and an inner portion of the upper surface of the focus ring 18, the chuck assembly is driven to ascend/descend so that an upper surface of the wafer becomes near to the upper electrode part 14 with a given interval therebetween.
The process gas is supplied into a gap between the upper and lower electrode parts 14, 16, namely, an upper side of the wafer W from a given side portion of the housing 10. Under such condition, when the radio frequency energy is applied to the upper and lower electrode parts 14, 16, the process gas provided therebetween is converted into a plasma state.
The process gas converted into plasma state reacts on an overall upper surface of the wafer W, or on a portion exposed from a formed photoresist pattern mask.
However, polymers in various forms or shapes generated by the above-mentioned reaction are indiscriminately deposited on the whole exposed area inside the housing 10, and such polymers"" deposition thickness gradually becomes serious by continuous or repetitive process execution. In other words, the polymer becomes in a state in which it may easily be separated from the surface inside the housing, and when this detached polymer flows inside the housing 10 and is positioned on the surface of the wafer W, the polymer reacts as a particle which causes a defect, etc.
Describing such problems on the polymer more in detail as shown in FIG. 2, it can be first seen that a hard polymer is continuously penetrated and deposited on the chuck assembly, despite a gap between the focus ring 18 and the insulation ring 20 for supporting a lower part of the focus ring 18 being under a close-stuck and covered state.
Such polymer deposited in the gap between the focus ring 18 and the insulation ring 20 degrades a function of the focus ring 18 in which the plasma area distribution on the wafer W is formed uniformly. Furthermore, such deposited polymer makes the wafer W loosened from the lower electrode part 16, or twisted, together with the focus ring 18.
This causes a process degradation such that a central portion of the wafer W is changed to a concave state by a fixing force of the lower electrode part 16, or that one side portion of the wafer W becomes loose; namely, the process on the wafer W is not executed equally.
Further, an outer portion of the focus ring 18 of the materials the wafer W, or a similar material, is gradually etched by the continuous process, and is changed to a radicalized shape, and guides the plasma area unequally, to thus again degrade the process.
Meanwhile, as that the baffle plate 22 is fixed to, and extending outward from, the chuck assembly, together with the chuck assembly it is driven to ascend/descend in a state where it is positioned adjacent to the inner wall of the upper and lower housing 10a, 10b. However, this causes an eddy flow phenomenon in a slit (s) of the baffle plate 22, or in a gap between the inner walls of the upper and lower housings 10a, 10b, to thus separate the polymer from its surface such that it floats, the polymer being deposited on the baffle plate 22 or on the upper and lower housings 10a, 10b inner wall.
In case such floating and flowing polymer flows onto the upper face of the wafer W, the portion where it is deposited has such a defect as being polluted or damaged etc. as mentioned above.
Further, the baffle plate 22 has a severe temperature change or deflection due to the process progression and stand-by time. Accordingly, the deposited polymer exists in a state where it easily breaks away. In other words, in case there is the eddy flow phenomenon in the ascending/descending driving of the chuck assembly as mentioned above, the polymer deposited on the surface is in a state such that it is easily separated therefrom and easily flows.
In the construction of the housing 10, the shield 12 is installed so as to cover only a given upper area portion of the upper housing 10a, and accordingly, a lower inner wall portion of the upper housing 10a and an inner wall portion of the lower housing 10b are exposed in the deposition of the polymer.
The polymer deposited on the shield 12 and the upper and lower housings 10a, 10b has a hard nature. Thus, the shield 12 can be separated from the upper housing 10a, be cleansed, and after that, can be reassembled. Therefore, its use may be easy. However, the upper and lower housings 10a, 10b are mutually combined with other constructions for assisting the process inside of the housing 10, and thus their separation and assembly are difficult. Also, since after a cleansing, their reassembly requires precision, there is a difficulty in a reassembly, and manpower, a lot of working time, and the careful attention of a worker are further required.
Accordingly, the present invention is directed to semiconductor device fabricating equipment using radio frequency energy that substantially obviates one or more of the limitations and disadvantages of the related art.
A primary object of the present invention is to provide semiconductor device fabricating equipment using radio frequency energy, in which a uniform distribution and process on a plasma area can be uniformly gained by preventing an edge portion of a focus ring from being etched in a radicalized shape, thereby maintaining a fixed disposition state of the focus ring and a wafer, and consequently a process can be obtained stably and uniformly, by preventing deposition of a polymer between the focus ring and an insulation ring.
Another object of the present invention is to provide semiconductor device fabricating equipment using radio frequency energy which is capable of simplifying each configuration corresponding to an ascending and descending driving of a chuck assembly, restricting an eddy flow phenomenon based on a flowing of a polymer and a particle at maximum, to thereby prevent a flowing of the polymer deposited on each surface inside of a housing and also to prevent a wafer defect containing pollution, or a damage to a wafer.
Still another object of the present invention is to provide a semiconductor device fabricating equipment using radio frequency energy, in which upper and lower housings are protected from a polymer being deposited indiscriminately, wherein disassembly and assembly of respective constructive components inside the housing are easy, to shorten the working time for equipment restoration and to increase the operation rate of the equipment, and a stabilize productivity.
To achieve these and other advantages, and in accordance with the purpose of the present invention, a semiconductor device fabricating equipment using radio frequency energy is composed of a housing which divides and forms the inside according that an upper electrode part having an applying of radio frequency energy is combined from an upper side thereof; a chuck assembly which has an applying of the radio frequency energy, fixes a provided wafer, and is installed so as to ascend and descend, oppositely to the upper electrode part, in the housing inside; and a baffle plate which is fixing-installed onto an inner wall of the housing so that an inner side edge portion is adjacent-positioned on a side wall of the chuck assembly with a given interval.
Further, it is desirable that the inner wall portion of the housing is divided into an upper housing and a lower housing, and that the baffle plate is fixingly-installed on a given portion of the upper housing""s upper side.
It is also desirable in the installation of the baffle plate that a shape of the upper housing inner wall has the shape of a short jaw extended and projected from a lower direction""s given position of an upper part to an inner side, and the baffle plate is preferably installed to be put on and supported by an upper part of the short jaw of the upper housing.
In addition, it is desirable to insert and install a shield having a tubular, or cylindrical, shape on the ledge of the upper housing so as to closely cover an inner wall of the upper housing.
Furthermore, in an inner wall of the lower housing containing a lower side inner wall from a short jaw position of the upper housing, it is set a liner having a tubular, or cylindrical, shape bent outwards so that its upper ending portion is put on an upper surface of the short jaw, to thus cover the surface thereof, and the baffle plate is positioned to be closely supported by the bent upper ending portion of the liner. Further, the shield is installed in a shape pressurizing and fixing an outer edge portion of the baffle plate, to thus fasten the shield, upper ending portions of its contacting and corresponding baffle plate and liner, and a short jaw portion of the upper housing by piercing a fastening instrument through them.
Meanwhile, the chuck assembly is constructed of: a lower electrode part, which closely supports a center portion of a lower surface of a positioned wafer, and which has a stepped shape so that an upper surface edge portion thereof is separated from a lower surface of the wafer; a focus ring whose inner lower surface is closely supported within a stepped surface of the lower electrode part, and whose inner upper surface portion has a stepped shape so that a lower surface of the wafer is inserted from above and stably positioned; and an insulation ring having a ring shape extended and projected outwards from a side part of the lower electrode part, wherein an inner upper surface portion of the insulation ring has a stepped shape so that a lower surface circumferential portion of the focus ring is inserted from above and is stably positioned.
The stepped portion of the insulation ring may be formed in a shape closely corresponding to an outer side wall of the focus ring and in a shape extended and projected therefrom. The inner upper surface of the insulation ring contact corresponding to the focus ring is formed so as to be positioned below the stepped portion of the lower electrode part. A corresponding lower portion of the focus ring can be formed in a shape projected along an outer side of the stepped portion of the lower electrode part.
Also, the stepped portion of the insulation ring is preferably formed to a depth of 1.5xcx9c2.2 mm from an upper surface of its outer side portion, and the outer side portion of the insulation ring is preferably extension-formed to a lower side thereof so as to form a side wall adjacent to an inner side portion of the baffle plate.